The present invention relates to a double-flow exhaust system for an internal-combustion engine, and more particularly, to an exhaust system having exhaust-gas-carrying pipes, and at least one muffler and catalyst housing.
DE 199 32 349 A1 shows a double-flow exhaust system of a motor vehicle in which two exhaust lines are guided together at the end into a common end muffler housing. A tail pipe, by way of which the exhaust gases are discharged to the outside, is fastened to the end muffler housing. As illustrated in FIG. 1 thereof, each exhaust line consists of several assemblies, such as the exhaust gas manifold, the catalyst and the end muffler which are assembled by way of corresponding exhaust pipes and flange-type connections.
An object of the present invention is to provide the assemblies of the exhaust system such that, on one hand, the free installation space in the area of the exhaust tail pipe is increased and, on the other hand, the mounting of the entire exhaust system is facilitated.
This object has been achieved by providing a separate end muffler for each exhaust line, the end mufflers being fluidically connected by at least one mountable connection pipe.
As a result of the fact that the two exhaust lines each have a separate end muffler, which both are fluidically connected by way of at least one mountable connection pipe, the space obtained between the two faces can be utilized for placing and developing the exhaust tail pipe. Furthermore, by separating the two exhaust lines in the area of the end muffler, the individual exhaust line can be assembled as a preassembled constructional unit in order to then complete it on the vehicle to form the entire exhaust system. By separating the U-shaped entire exhaust system in the area of the end muffler, a transport of the preassembled constructional unit also becomes possible without any problem.
A first connection of the two end mufflers takes place by way of a T-pipe piece which, via its two first pipe ends, is connected with the two end mufflers, while the third pipe end is used as an exhaust gas outlet. In this embodiment, a tail pipe with a tail pipe cover is mounted on the third pipe end of the T-piece.
Advantageously a second connection pipe between the two end mufflers contributes to the muffling of noise, particularly of the low-frequency fractions in the low rotational speed range. Simultaneously, a torque increase is obtained in the low rotational speed range. Here, the course and the position in the rotational speed band of the torque increase and of the noise muffling can be significantly influenced by the targeted adaptation of the pipe length and of the pipe cross-section.
The mountable second connection pipe consists of two connecting pieces connected with the respective end muffler housing, onto which connecting pieces a sliding sleeve is pushed and whose axial positioning or securing can be achieved, for example, by a clamp.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.